1. Field of the Invention
The invention concerns a method for drying a gas which has been compressed by a compressor.
2. Description of the Related Art
Compressed gas, for example, air, usually has a high moisture content at the outlet of the compressor. This moisture can be disadvantageous to the network of pipes and undesirable in certain applications. Therefore, it is useful, if not necessary, to dry the compressed air.
According to a known method, described in BE-A-1005764, a compressed gas is driven through a drying agent. Already used drying agent is simultaneously regenerated by driving a part of the gas compressed by the compressor, tapped directly from the outlet of the compressor, through it. This gas absorbs water from the already used drying agent. The water is then condensed and separated by cooling the gas. Then the gas is mixed again with the compressed gas to be dried.
Such a method is disadvantageous in that the regeneration is carried out with a gas which is still moist. As a result, the drying or regeneration of the drying agent is rather slow. Consequently, the regeneration of an amount of drying agent takes relatively long compared to the time required to saturate the same amount of drying agent with moisture during the drying of the compressed gas.
Also, a relatively high regeneration temperature is necessary to make the regeneration process take place at an acceptable rate. Due to the operating conditions of the compressor, for example, a low service pressure and/or frequent load/no-load running, said high regeneration temperature is not always available.